This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-017175, filed Jan. 25, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a camera comprising a collapsible mount type photographic lens tube with a lens barrier.
2. Description of the Background Art
The camera comprising a collapsible mount type photographic lens tube with a lens barrier comprises a lens protection mechanism by the lens barrier and a collapsible function by the collapsible mount type photographic lens tube. For this reason, when the camera is not used, a photographic lens is safely protected. The camera has a thin camera body. As a result, the above described camera is extremely easy to carry and good in portability.
FIG. 1 is a sectional view of a main part showing an example of a camera comprising a conventional collapsible mount type photographic lens tube with a lens barrier. In FIG. 1, reference numeral 50 denotes a camera main body, reference numeral 60 denotes a collapsible mount type photographic lens tube, and reference numeral 70 denotes a lens barrier.
The collapsible mount type photographic lens tube 60 can be operated so as to advance and retreat a moving tube frame 62 holding a photographic lens 61 along a photographic optical axis O. That is, when the camera is not used, the photographic lens 61 retreat into a collapsed position P1 inside the camera main body 50 and is put into a housed state. On the other hand, when the camera is used, the photographic lens 61 advances to a position shown by a two-dot chain line, that is, up to a photographing position P2 outside of the camera main body 50 and is put into a state of being able to take a photograph.
The lens barrier 70 is usually attached to the front surface of the camera main body 50 in such a manner as to be movable in a direction (a vertical direction to the paper surface) orthogonal to the photographic optical axis O. That is, when the camera is not used, the lens barrier 70 moves to a closed position covering the front surface of the above described photographic lens 61, so that it is put into a state of protecting the photographic lens 61. On the other hand, when the camera is used, the lens barrier 70 moves to an open position that is shifted from the front surface of the photographic lens 61, so that the front surface of the photographic lens 61 is opened, thereby making it possible to take a photograph.
In the camera comprising the conventional collapsible mount type photographic lens tube 60 with the lens barrier 70, an outer surface shape of a front side end portion of the collapsible mount type photographic lens tube 60 at the time when the photographic lens 61 retreats to the collapsed position P1 is provided in such a manner as to be an almost flat surface which is vertical to the photographic optical axis O at its front surface as shown in FIG. 1. On the other hand, an inner surface shape of the lens barrier 70 has usually a concave curved surface, as shown in FIG. 1, so as not to touch an outer periphery of the moving tube frame 62 of the above described collapsible mount type photographic lens tube 60 and also to secure a mechanical strength capable of enduring an external force. For this reason, the inner surface of the lens barrier 70 on the photographic optical axis O and the outer surface of the photographic lens 61 are opposed to each other at a relatively large distance G. For this reason, a thickness of the camera body inclusive of the lens barrier is relatively large, thereby preventing the camera from becoming thinner.
An object of the present invention is to provide a thinner camera.
That is, the camera according to the present invention is a camera in which a lens barrier can be arranged so as to be brought as closely as possible near to a position of an approachable limit to a front side end portion of a photographic lens tube along a photographic optical axis and, by a portion equivalent to a distance that could be approached, a total thickness dimension of a camera main body and the lens barrier can be made smaller. In this way, the camera can be thinned.
A camera according to an aspect of the present invention comprises: a camera main body; a photographic lens tube having a photographic lens which is mounted on a front side of the above described camera main body and provided so as to be able to advance and retreat between a collapsed position retreated to the backside of the camera main body and a photographing position advanced to the front side of the above described camera main body; a lens barrier mounted on the front surface of the camera main body and provided so as to be movable in a direction to substantially vertically cross the photographic optical axis (for example, in the direction along a horizontal axis H comprising a liner line or the direction along the horizontal axis comprising a curved line curved inside a horizontal surface) between a closed position for closing the front surface of the photographic lens so as to cover the photographic lens retreated to the collapsed position when it is not used and an open position for opening the front surface of the photographic lens so as not to prevent the movement of the photographic lens advancing to the photographing position when it is used, wherein the outer surface shape of the front side end portion of the photographic lens tube at the time when the photographic lens retreats to the collapsed position is formed in a shape (including a convex cylindrical surface or a spherical surface and the like) corresponding to the inner surface shape (including a concave cylindrical surface or a spherical surface and the like) of the lens located at the closed position.